The term "de missions" refers to the act of delegating or assigning a task to someone. The antonyms of this word would include terms such as "retain," "assume," "hold onto," or "keep." These words suggest that instead of passing a task or responsibility onto someone else, one would choose to keep it for themselves. Other antonyms might include actions that involve taking back delegated tasks or responsibilities, such as "retract," "withdraw," or "rescind." It's important to choose the right antonym for "de missions" depending on the context in which the term is being used, as specific antonyms may be more appropriate in some situations than others.